Augmented reality technique (AR) is a new technique developed on the basis of virtual reality, which improves a user's perception of the real world through information provided by a computer system, and superimposes virtual objects, scenes or system prompt information generated by a computer on a real scene, thereby achieving “augmenting” the reality. The AR superimposes virtual objects or non-geometrical information about real objects generated by the computer on a scene in the real world, thereby achieving augmenting the real world. Meanwhile, because the connection with the real world is not cut off, the interaction manner appears to be natural.
Such a technique is usually applied to a head-mounted display device, and has the characteristics of virtual and real combination, real-time interaction and 3D registration.
Virtual and real combination: the AR can extend the display screen to the real environment, superimposing the computer window and icons on real objects, and performing operations by eyes gazing or gesture pointing; it can interactively change the shape and appearance of a 3D object in the panorama view of the user according to the current task or as required; it can produce the augmentation effect similar to X-ray fluoroscopy for the real object by superimposing a virtual scene; it can directly insert map information into a real landscape to guide the actions of a driver; and it can invoke to see the outdoor scene through a virtual window, enabling the wall to seem transparent.
Real-time interaction: the AR extends the interaction from an accurate position to the entire environment, developing from a simple person-facing-screen communication to merging oneself into the surrounding space and objects. Using an information system is no longer a conscious and deliberate separate action, and is naturally integrated with the current activities of the person. The interactive system is no longer limited to a specific position, and is expanded to the entire environment.
3D registration: namely, adjusting the augmented information generated by the computer according to the movement of the user in the 3D space.
Most of the existing virtual reality display methods are in an addition form, namely, a virtual scene is superimposed on the real scene to help the person to get better interactive experience. However, in some cases, some interference information of the real scene needs to be shielded off or weakened to highlight some real subjects of interest.